Salting-out of alkanols by inorganic electrolytes

Abstract

The free energies, entropies and enthalpies associated with the salting-out of alkanols (mainly butanol) by eight inorganic electrolytes have been determined at 20°C. The results are discussed in terms of the scaled particle theory (in the case of 1 : 1 electrolytes) and the thermodynamic theory of McDevit and Long. It is concluded that alternative approaches to the treatment of salting-out would be desirable. A simple, semi-empirical method for the calculation of salting coefficients is proposed. It is based on the effect which the electrolyte has on the surface tension of the solvent (water) and is found to be relatively successful for many systems.